Microsoft today began offering Mac users its OneNote application free of charge, making rumors of last week a reality.

The OneNote app has been published to the Mac App Store, the OS X version of Apple's better-known App Store for the iPhone and iPad. Microsoft also scratched off the price tag from the Windows desktop version of OneNote, which had cost $70 as a standalone application.

"Microsoft releasing OneNote for the Mac is clear evidence of an ecosystem play [by the company] because it's important to have clients on major platforms as opposed to just ones that are growing rapidly," Ross Rubin, of Reticle Research, said in an email.

The free versions are limited to home and school use, and are not licensed for business purposes. Only those copies of OneNote that are part of a commercial-class version of Office 2013 or a business-grade Office 365 plan can be used for work at work.

Also today, Microsoft released a browser toolbar add-on for grabbing Web content and placing it in OneNote, and shipped Office Lens, a Windows Phone-only app that captures documents snapped with the smartphone's camera.

Microsoft couched the free OS X and Windows OneNote as part of its all-along plan to push the note-taking application to as many platforms as possible. "We've made it easier to use OneNote no matter what platform you're on, and easier than ever to send anything into OneNote," wrote David Rasmussen, a partner group program manager with the team, on a blog today.

That strategy mimics Evernote's, the company whose same-named flagship note-taking software is also on every meaningful platform, including Windows 8's "Metro" tile-based user interface (UI).

One analyst last week saw the then-rumored move as a defensive play by Microsoft to lock customers inside the Redmond gate. "Evernote's become a hugely successful product and Microsoft needs to keep as many people as possible from relying on applications that compete with its Office components," said Michael Silver of Gartner in a Thursday interview.

Evernote declined to comment on Microsoft's OneNote moves of Monday.

Wes Miller, an analyst at Directions on Microsoft, also connected Microsoft's more-OneNote strategy to Office. "Microsoft wants mindshare and market share and to do that it needs to establish a broader market [for OneNote]," Miller said last week. "If you have to buy all of Office to get [OneNote], you're losing any of those potential customers who will not buy all of Office."